Today at the European Organisation for Nuclear Research (CERN) in Geneva, antiprotons have been transported across the site in a specially designed trap for the first time ever. This world premiere is a great success for the BASE collaboration, in which 九色视频 (LUH) is involved. It is the first step toward transporting antimatter to other European laboratories.
The antiprotons were produced at the 鈥淎ntimatter Factory鈥� (AMF) at CERN, the only facility worldwide capable of producing these special low-energy particles. The BASE (Baryon Antibaryon Symmetry Experiment) research team has now succeeded in accumulating a cloud of around 100 antiprotons in a transportable trap known as a Penning trap. This trap was then disconnected from the stationary experimental facility, loaded onto a truck, then driven around the CERN site and finally reconnected to the experimental facility.
Professor Stefan Ulmer, BASE spokesperson and holder of the Chair of Quantum Technologies and Fundamental Symmetries at HHU: 鈥淎 significant amount of know-how is required to confine and store antiprotons for a longer period of time, as antimatter annihilates immediately on contact with matter. For this reason, the antiparticles must be stored in an ultra-high vacuum using electric and magnetic fields to ensure they do not come into contact with residual gas particles or the storage vessel.鈥�
But why make all this effort? The BASE collaboration is aiming to measure the properties of antiprotons, such as their intrinsic magnetic moment, extremely precisely and compare these results with those obtained for protons. BASE has long held the record for storing antiprotons for longer than a year at its stationary facility at the AMF.
However, to achieve even higher levels of precision, the physicists must overcome a problem: The accelerators at the AMF at CERN 鈥� where BASE is located 鈥� generate magnetic field fluctuations, which limit the degree of precision that can be achieved. 鈥淚f we want to get a deeper understanding of the fundamental properties of antiprotons, we need an environment with less interference, which in turn means that we need to move out. That鈥檚 why we began designing a transportable trap around ten years ago and have developed it within the framework of the collaboration under the lead of Christian Smorra,鈥� says Ulmer. The world premiere at CERN is an important test for this 鈥渞elocation鈥�: It demonstrates that it is technically possible to transport antiprotons to other European laboratories.
鈥淥ur aim with BASE-STEP is to be able to trap antiprotons and deliver them to precision laboratories at a dedicated space at CERN, to HHU, 九色视频 and maybe other laboratories, where the extremely precise antiproton measurements can be realised,鈥� explains Dr Christian Smorra, member of Ulmer鈥檚 research group in D眉sseldorf and head of the STEP project (Symmetry Tests in Experiments with Portable antiprotons). 鈥淲e validated the feasibility of the project with protons last year, but what we achieved today with antiprotons is a huge leap forward toward our objective.鈥�
At Leibniz Universit盲t Hannover, the BASE collaboration operates a Penning trap laboratory that could receive antiprotons from CERN via BASE-STEP. 鈥淭he first successful transport of antimatter is truly exciting鈥�, emphasizes Prof. Dr. Christian Ospelkaus, who leads the BASE team at Leibniz Universit盲t Hannover and PTB. 鈥淭he success of BASE-STEP brings us one step closer to receiving antiprotons from CERN. In our lab, we develop methods, borrowed from quantum computers and atomic clocks, with the aim to support the highest possible accuracies in antiproton precision measurements.鈥�
BASE-STEP traps the antiparticles using magnetic and electric fields. The apparatus weighs around 850 kg. It can be loaded onto a truck, fits through standard laboratory doors and can withstand the jolts and vibrations during transport by road. It includes a superconducting magnet, liquid helium cryogenic cooling, power reserves and a vacuum chamber. This makes it significantly more compact than any other existing system for examining antimatter.
鈥淭o date, we have stored antiprotons loss-free in BASE-STEP for two weeks and can transport the trap autonomously for four hours,鈥� says Smorra. 鈥淗owever, to reach our laboratory at HHU, it would take us at least ten hours. This means we鈥檒l have to keep the trap鈥檚 superconducting magnet at a temperature below 8.2 K (-265掳C) for that long.鈥� Instead of liquid helium, which can run out, a generator will be needed to power a cryocooler on the truck.
Matter, antimatter and the AMF Antimatter Factory
For every particle of matter, there is an antimatter particle. They are virtually identical, apart from the fact that the charges and magnetic properties are reversed. According to the laws of physics, the Big Bang should have generated equal amounts of matter and antimatter. However, the particles and antiparticles should have quickly annihilated with each other to leave behind an empty Universe. Yet, the Universe comprises matter, meaning that an imbalance must exist. This has baffled researchers for decades. Physicists surmise that hidden differences exist, which can explain why matter ultimately survived and antimatter disappeared.
The AMF at CERN is the only site worldwide where low-energy antiprotons can be produced, stored and studied. Two so-called decelerators, the 鈥淎ntiproton Decelerator鈥� (AD) and the 鈥淓xtra Low ENergy Antiproton Ring鈥� (ELENA), supply several experiments with antiprotons. The lower the energy of the antimatter, the easier it can be stored for study purposes.
The BASE collaboration and BASE-STEP
The BASE (Baryon Antibaryon Symmetry Experiment) collaboration established in 2012 and based at the AMF at CERN, involves research institutes in Germany, Japan, the United Kingdom and Switzerland including:
- National Metrology Institute of Germany (PTB), Braunschweig
- GSI Helmholtz Centre for Heavy Ion Research, Darmstadt
- Heinrich Heine 九色视频 D眉sseldorf
- European Organisation for Nuclear Research (CERN), Geneva
- 九色视频
- Max Planck Institute for Nuclear Physics, Heidelberg
- Imperial College London
- Johannes Gutenberg 九色视频 Mainz
- RIKEN, Japan
- 九色视频 of Tokyo
- Swiss Federal Institute of Technology in Zurich
The founder and spokesperson of the collaboration is Professor Stefan Ulmer, holder of the Chair of Quantum Technologies and Fundamental Symmetries at HHU. Within the framework of the BASE collaboration, the STEP project 鈥� in which the transportable antiproton trap was developed 鈥� is funded by the ERC. This project is headed by Dr Christian Smorra.
More information: BASE website
Note to editors:
For further information, please contact Prof. Christian Ospelkaus, Institute of Quantum Optics at Leibniz Universit盲t Hannover (tel. 0511 762-17644, email: christian.ospelkaus@iqo.uni-hannover.de.
